Ultrasound simulation technique as state-of-health estimation method of lithium-ion batteries

Ultrasound is a non-destructive technique recently proposed to estimate Lithium-ion batteries degradation. However, recent research has been devoted towards understanding the physical phenomena behind the ultrasonic wave propagation through a Lithium-ion battery. To achieve this, the second-order-scalar elastic and acoustic wave equations are solved with explicit and implicit finite difference method, considering the interfaces between materials with different physical properties. Results showed that implicit method presents less noise than the explicit scheme. In addition, changes in the physical properties of battery materials that occur in charge and discharge processes, highly affect the ultrasonic wave propagation inside the battery. Finally, this study demonstrates the feasibility of using numerical methods as a precursor of battery degradation estimator.